To keep abreast with the constantly progressive optical technology, currently the projectors are applied extensively in various occasions, e.g. the conference, technical seminar and demonstration, to present the multimedia image contents. For presenting the projected image clearly and vividly, the projection brightness of the projector is a very important consideration. By and large, the higher the projection brightness is, the better the projection effect will be. Consequently, how to use a simple and convenient method to improve the brightness of the light source inside the projector, as well as how to adjust and calibrate the light source to the optimal focal position have become extremely important issues.
The digital light processing (DLP) projector utilizes the beam splitter to separate the light provided by the light source adjusting device (i.e. the lamp of the projector) into three primary colors and then combine the beams and mix the colors, thereby generating the required optical image. The light source adjusting device plays a significantly critical role in providing the brightness and the uniformity of light. As a consequence, for providing the projector with a better projection image quality, the light source adjusting device thereof is as important as the optical lens thereof.
Please refer to FIG. 1, which is a schematic view showing the light source adjusting device of the conventional projector. The light source adjusting device 10 includes a lamp 11 whose front end is directly fastened on the frame 13 through the screw 12. The lamp 11 is disposed inside the projector (not shown) by means of the frame 13. The position of the lamp 11 in such a structure is not adjustable. If the position of the lamp is not desirable after the light source adjusting device 10 is installed into the projector, the light source adjusting device 10 must be re-installed.
To improve the lighting efficiency of the light source adjusting device in the projector, a sequential color recapture (SCR) technique is adopted in the prior art to achieve the desired lighting efficiency. Please refer to FIG. 2, which is a schematic view showing the light source adjusting device of the conventional projector using the sequential color recapture technique. As shown in FIG. 2, a reflector 24 is disposed at the inner side of the opening 23 of the integration rod 22, so that the incidence light provided by the lamp 25 merely goes through a tiny aperture 26 of the integration rod 22 by recapturing the reflected light. Such technique certainly improves the lighting efficiency of the light source adjusting device in the projector. However, the focal point of the lamp 25 must be precisely positioned at the center of the integration rod 22 to lower the lighting loss. Because the position of the lamp fails to be dynamically adjusted in the light source adjusting device of the conventional projector, such technique is still hard to be implemented. Therefore, such issue would be overcome if the lamp could be dynamically adjusted to the focal position.
Please refer to FIG. 3, which is a schematic view showing the outside of a projector. The projector 30 includes a housing 31, a cover 32, an opening 33 and a plurality of control buttons 34. All of the internal components of the projector 30 are placed inside the housing 31. After all of the internal components are assembled, the cover 32 is used to cover the projector 30 so that the assembly of the projector 30 is completed. The cover 32 is located on the front side or the rear side of the housing 31 of the projector 30. Depending on the design of the projector 30, the opening 33 is used for the light source to pass therethrough. The control buttons 34 are used to control all functions of the projector 30. The number and functions of the control buttons varies with the model of the projector 30. Owing to the structural complication and arduous processing regarding the adjusting module of the light source adjusting device in the prior art, the housing of the entire projector must be disassembled before the lamp is adjusted. Hence, the assembly of the housing could only be proceeded after the completion of the lamp adjustment. In addition to the time spent for adjusting the lamp position, the reassembly of the housing also costs plenty of time and labor. This causes a hurdle in the production process and a hike on the cost. To cope with the limitation, the implementation of a modified lamp adjusting device is indispensable.
Based on the above, in order to overcome the drawbacks in the prior art, the present invention provides an improved light source adjusting device, which obviously enhances the adjustment of the lamp to a focal position.